Frequently Asked R Interview Questions and Answers

by DataFlair Team ·
Published November 6, 2017
· Updated June 27, 2019

1. Objective

As we have already discussed R in deep in our previous blogs. Now in this respective blog, we will provide you 30 frequently asked R interview questions and answers including advanced terminologies to advanced long answers. These questions will definitely help you to sort out your each and every small concept.

Frequently Asked R Interview Questions and Answers

2. Top 30 R Interview Questions and Answers

Q.1. Explain how you can start the R commander GUI?

rcmdr command is used to start the R Commander GUI. Once R is running, simply loading the Rcmdr package by typing the command library(Rcmdr) into the R Console starts the R Commander graphical user interface.

Object-oriented programming (OOP) is a programming paradigm based on the concept of “objects”, which may contain data, in the form of fields, often known as attributes; and code, in the form of procedures, often known as methods. A feature of objects is that an object’s procedures can access and often modify the data fields of the object with which they are associated (objects have a notion of “this” or “self”)

Procedural programming is a programming paradigm, derived from structured programming, based on the concept of the procedure call. Procedures, also known as routines, subroutines, or functions (not to be confused with mathematical functions, but similar to those used in functional programming), simply contain a series of computational steps to be carried out. Any given procedure might be called at any point during a program’s execution, including by other procedures or itself.

R is an open source programming language and software environment for statistical computing and graphics that is supported by the R Foundation for Statistical Computing. The R language is widely used among statisticians and data miners for developing statistical software and data analysis.

After data preparation, start running the model, analyze the result and tweak the approach. This is an iterative.

Validate the model using a new data set.

Start implementing the model and track the result to analyze the performance of the model over the period of time.

Q.6. What is Compiler in R?

A compiler is computer software that transforms computer code written in one programming language (the source language) into another computer language (the target language).

Q.7. What is Mean in R?

The mean is the average of the numbers: a calculated “central” value of a set of numbers.
To calculate: Just add up all the numbers, then divide by how many numbers there are.

Q.8. What is Median in R?

The Median is the “middle” of a sorted list of numbers. BUT, with an even amount of numbers, things are slightly different. In that case, we find the middle pair of numbers, and then find the value that is halfway between them. This is easily done by adding them together and dividing by two.

Q.9. What is Variance in R?

The Variance is defined as the average of the squared differences from the Mean.

Factor variables are categorical variables that hold either string or numeric values. Factor variables are used in various types of graphics and particularly for statistical modeling where the correct number of degrees of freedom is assigned to them.

Q.13. What is the difference between the data frame and a matrix in R?

Data frame can contain heterogeneous inputs while a matrix cannot. In the matrix, only similar data types can be stored whereas in a data frame there can be different data types like characters, integers or other data frames.

Q.14. What are the data types in R on which binary operators can be applied?

To get or set a single attribute, you can use the attr() function. This function takes two important arguments. The first argument is the object we want to examine, and the second argument is the name of the attribute we want to see or change. If the attribute we ask for doesn’t exist, R simply returns NULL.

Q.17. What is length function in R?

R length Function. length() function gets or sets the length of a vector (list) or other objects. length() function can be used for all R objects. For an environment, it returns the object number in it. NULL returns 0.

Q.18. What is Data Structure in R?

A data structure is a specialized format for organizing and storing data. General data structure types include the array, the file, the record, the table, the tree, and so on. Any data structure is designed to organize data to suit a specific purpose so that it can be accessed and worked with in appropriate ways

Q.19. What is afile in R?

R is a file extension for a script written in R. R is a programming language designed for statistical computing and graphics purposes. Contains code that can be executed within the R software environment

Q.20. What is an arbitrary function in R?

Arbitrary function means any function. But generally, it refers to a function belongs to the same class of functions we are discussing ( its freedom is limited ). For example, when talking about continuous real-valued functions defined on the bounded closed interval of the real line, by an arbitrary function may refer to a function of the same type.

An arbitrary R object, or an object inheriting from class “table” for the as.data.frame method. … a character vector giving the row names for the data frame. responseName. The name to be used for the column of table entries, usually counts.

Q.22. What is the tree in R?

R-trees are tree data structures used for spatial access methods, i.e., for indexing multi-dimensional information such as geographical coordinates, rectangles or polygons. The R-tree was proposed by Antonin Guttman in 1984 and has found significant use in both theoretical and applied contexts.

Q.23. Explain if control statements in R?

if If this condition is true, then carry out a certain task. R makes it even easier: You can drop the word then and specify your choice in an if statement.

R – Packages. R packages are a collection of R functions, complied code and sample data. They are stored in a directory called “library” in the R environment. By default, R installs a set of packages during installation.

So, this was all in R Interview Questions and Answers. Hope you like our explanation.

3. Conclusion – R Interview Questions and Answers

Hence, in this R Interview Questions and Answers, we discussed the most asked interview Questions in R. Also, these R Interview Questions and Answers proved beneficial for both freshers and experienced. Still, if you want to add more questions for R Interview, tell us through Comments.